Do not purchase this modem for use with Comcast!! I purchased this modem, off of Comcast's approved list in January, to replace my leased modem from Comcast. I worked fine until April,1. That was when, in my area, Comcast began their update from IPv4 to IPpv6. This modem has a known error in its firmware in which it will not allow Comcast to update it firmware to be able to work with the IPv6 changes. I have spent over two months trying to get Netgear to either fix the modem, update the firmware, or refund my money. So far it has amounted to nothing. Netgear has sold a bad modem and is now trying to covered up their mistake by pointing the finger at Comcast or drowning their support customers in endless requests for screenshots that have already been provided and other useless and repetitive information request. I now seem to be between a rock and hard place and it would appear that I will have to purchase a modem from a different manufacture that will actually work.
1 August Update: After 4 months of going back and forth with Netgear and having them send me two different modems after they accepted that the problem was the modem, not Comcast service, I finally gave up. I sent their modems back and requested a refund. As it stands right now, Netgear has cut all communications with me, will not respond to my voicemails or emails. So I am screwed out of $90. If I could I would give the company and modem zero stars. Avoid at all cost.